This invention relates generally to inflatable safety restraint devices such as airbag installations for automobiles and, more particularly, to airbag retention collars such as for attaching inflatable airbag cushions in airbag module assemblies employing side discharge inflator devices.
It is well known to protect a vehicle occupant by means of safety restraint systems which self-actuate from an undeployed or static state to a deployed state without the need for intervention by the operator, i.e., “passive restraint systems.” Such systems commonly contain or include an inflatable vehicle occupant restraint or element, such as in the form of a cushion or bag, commonly referred to as an “airbag cushion.” In practice, such airbag cushions are typically designed to inflate or expand with gas when the vehicle encounters a sudden deceleration, such as in the event of a collision. Such airbag cushion(s) may desirably deploy into one or more locations within the vehicle between the occupant and certain parts of the vehicle interior, such as the doors, steering wheel, dashboard or the like, to prevent or avoid the occupant from forcibly striking such parts of the vehicle interior.
Various types or forms of such passive restraint assemblies have been developed or tailored to provide desired vehicle occupant protection based on either or both the position or placement of the occupant within the vehicle and the direction or nature of the vehicle collision. Automotive passenger side airbag installations generally incorporate an airbag module assembly having an inflator device within a module canister and an inflatable airbag cushion adapted to inflate out a side of the module canister. In one currently used passenger side airbag module assembly configuration the inflatable airbag cushion is adapted to inflate out a top side of the module canister, often referred to as a “top mounted” airbag cushion. Such a module assembly is installed in the dashboard of the automobile close to the windshield. Upon activation, the inflator device releases inflation gas which inflates the airbag cushion. The top mounted airbag cushion initially inflates toward the windshield and then rapidly rolls down the dashboard in a direction toward the passenger.
Current passenger side airbag module assemblies often incorporate a generally elongated and cylindrically shaped end discharge inflator device within a module canister. An “end discharge” inflator device refers to an inflator device including an inflator diffuser element, for diffusing the thrust of the exiting inflation gas, typically disposed over an inflation gas exit area at one of the opposing ends of the cylindrical inflator device. The end discharge inflator device is generally positioned within the module canister, and an additional module diffuser element is typically disposed between the end discharge inflator device and the inflatable airbag cushion.
A side discharge inflator device is an alternative inflator device design to the end discharge inflator devices discussed above. In a side discharge inflator device, the inflation gas exit area and the inflator diffuser element, if used, are not located at one of the opposing ends of the cylindrical inflator device, but typically centrally located on the cylindrical body of the inflator device. An advantage of a side discharge inflator device is that the inflation gas can be released in a central area of the airbag module assembly, as compared to an end area, and directly into a central area of the associated inflatable airbag cushion. However, a more concentrated discharge in a central area of the inflatable airbag cushion may not be desirable if efforts are directed to obtain a more uniform airbag cushion deployment to minimize or avoid inflation forces on the automobile windshield and/or minimize or avoid risk of injury to an out-of-position occupant, i.e., an occupant not seated in the optimal passenger riding position. In addition, the inflation gas exiting a side discharge inflator device can cause or result in bell-mouthing of the module canister. “Bell-mouthing” refers to a deformation of the module canister, generally around the open end, or “mouth,” of the module canister, as a result of the forces produced during and associated with bag deployment.
There is a need for a passenger side airbag module assembly that more uniformly distributes inflation gas and the resulting inflation forces to a full width of the inflating airbag cushion. More particularly, there is a need for an airbag module assembly that incorporates a side discharge inflator, is relatively easy to assemble and promotes distribution of inflation gas across a width of the airbag cushion during earlier stages of deployment to reduce inflation forces exerted on the automobile windshield and/or minimize or avoid risk of injury to an out-of-position occupant.
There is also a need for a passenger side airbag module assembly having increased support in an area generally surrounding the inflator diffuser of a side discharge inflator such as to reduce, minimize or prevent bell mouthing of the module canister.